A wearable medical device comprising: a plurality of patient interface components each configured to interface with a patient; a first patient interface component of the plurality of patient interface components, the first patient interface component comprising a first sensing electrode for receiving one or more signals from a first patient, and a first therapy electrode for delivering a first treatment to the first patient; a second patient interface component of the plurality of patient interface components, the second patient interface component comprising a second sensing electrode for receiving one or more signals from a second patient; and one or more processors in communication with the plurality of patient interface components, the one or more processors configured to detect a first condition of the first patient based at least in part on the one or more signals from the first patient, cause the first treatment to be delivered to the first patient, wherein the first treatment is based at least in part on the detected first condition of the first patient, and detect a second condition of the second patient based at least in part on the one or more signals from the second patient.

A WCD system is configured to detect when a therapy administered to a patient by the WCD system is unsuccessful, and in response determine whether to send notifications to remote non-witness responders. The WCD system may be configured to decide to send such notifications after the WCD system determines it has administered a predetermined number of unsuccessful shocks to the patient. The predetermined number of unsuccessful shocks may be the maximum number of unsuccessful shocks the WCD system will administer to a patient, or every Xth shock (e.g., 3.sup.rd shock). The WCD system can be configured to periodically resend the notification. The notifications may be in form of SMS, voice messages, emails, app notifications, etc. sent to cell phones, smartphones, computers, laptops, tablets etc. of the responders either directly, via a server, or via a CAD-coupled server.

In embodiments, an external defibrillator has an electrical circuit with a special output stage for the high-voltage defibrillation pulse. The output stage includes switches that can turn on for delivering the pulse, and off during all other times. The output stage also includes a diverting resistance to divert electrical current that could leak into the patient while a capacitor is being charged. An optional detector may notify if a component is malfunctioning. An advantage can be that an external defibrillator may be created according to embodiments that uses, in its output stage, semiconductor switches instead of relays. As semiconductor switches weigh less and occupy less volume than relays, an external defibrillator according to embodiments may have less weight and volume. Especially in wearable defibrillator applications, less weight means less effort to carry and less volume means easier concealment under clothing.

An adherent device to monitor a patient for an extended period comprises a breathable tape. The breathable tape comprises a porous material with an adhesive coating to adhere the breathable tape to a skin of the patient. At least one electrode is affixed to the breathable tape and capable of electrically coupling to a skin of the patient. A printed circuit board is connected to the breathable tape to support the printed circuit board with the breathable tape when the tape is adhered to the patient. Electronic components electrically are connected to the printed circuit board and coupled to the at least one electrode to measure physiologic signals of the patient. A breathable cover and/or an electronics housing is disposed over the circuit board and electronic components and connected to at least one of the electronics components, the printed circuit board or the breathable tape.

A wearable cardioverter defibrillator (“WCD”) system may output a loud sound after detecting and validating a shockable cardiac arrhythmia. In such embodiments, however, the WCD system might not sound a loud alarm before validating the arrhythmia thoroughly, i.e. for a longer time, thus giving the arrhythmia a further chance to self-terminate. The WCD system may thus detect more robustly the cardiac arrhythmias that do not self-terminate quickly. Such arrhythmias that self-terminate quickly may occur from likely harmless events occurring multiple times in the daily life of the patient, such as the patient becoming “winded” from climbing stairs. In embodiments the WCD system may notify the patient only discreetly, or even not at all. The lack of sounding such a loud alarm responsive to such events reduces the overall number of times in which the patient experiences unwanted attention by others, embarrassment, loss of privacy and dignity, and so on.

In embodiments, a wearable cardiac defibrillator system includes an energy storage module configured to store a charge. Two electrodes can be configured to be applied to respective locations of a patient. One or more reservoirs can store one or more conductive fluids. Respective fluid deploying mechanisms can be configured to cause the fluids to be released from one or more of the reservoirs, which decreases the impedance at the patient location, and decreases discomfort for the patient. In some embodiments an impedance is sensed between the two electrodes, and the stored charge is delivered when the sensed impedance meets a discharge condition. In some embodiments, different fluids are released for different patient treatments. In some embodiments, fluid release is controlled to be in at least two doses, with an intervening pause.

A wearable cardioverter defibrillator (WCD) comprises a plurality of electrocardiography (ECG) electrodes, a right-leg drive (RLD) electrode, and a plurality of defibrillator electrodes to contact the patient's skin when the WCD is delivering therapy to the patient, a preamplifier coupled to the ECG electrodes and the RLD electrode to obtain ECG data from the patient as one or more ECG vectors, a high voltage subsystem to provide a defibrillation voltage to the patient through the plurality of defibrillator electrodes, and an impedance measurement circuit to measure an impedance across a first pair of ECG electrodes, wherein the impedance measurement circuit is to apply a balancing impedance across a second pair of ECG electrodes when an impedance of the second pair of ECG electrodes is not being measured.

An automatic external defibrillator includes an AED body having a pair of defibrillation pads applied to a chest of a rescuee to apply an electric shock to the rescuee; and a pulse wave sensor unit connected to the AED body to detect a pulse wave in a head of the rescuee.

This document describes an electrode assembly for use with a defibrillator, the electrode assembly comprising at least one electrode including a first surface that can be affixed to either of a pediatric patient and an adult patient and a second surface, wherein a majority of the second surface includes pictorial instructions related to use of the electrode assembly; and a chest compression sensor attached to the at least one electrode, wherein the at least one electrode is configured to be used on an adult patient when the electrode assembly is in a first orientation, and wherein the at least one electrode is configured to be used on a pediatric patient when the electrode assembly is in a second orientation.

A method for measuring a myocardial physiologic parameter according to an embodiment includes placing an at least partially convex portion of a spectral sensor against an intercostal space of a human over a heart of the human and measuring the physiologic parameter of a myocardium of the heart with the spectral sensor over time during an emergency medical event. The spectral sensor may be configured to determine and visually display a suggested position adjustment for directing the spectral radiation more directly toward the tissue of interest (e.g. the myocardium), and/or for placing the operative elements of the spectral sensor closer to the tissue of interest (e.g. the myocardium).